powerpc64 system-clang-8 based context: x11-toolkits/qt5-declarative fails to build in poudriere: /usr/local/lib/qt5/bin/qlalr segmentation faults in std::type_info::~type_info() () from /usr/local/lib/gcc8/libstdc++.so.6

[Mark Millard]

On 2019-May-24, at 11:25, Mark Linimon <linimon at lonesome.com> wrote:

> On Thu, May 23, 2019 at 10:33:35PM -0700, Mark Millard via freebsd-toolchain wrote:
>> That is no matter what the system compiler is for powerpc64.
>> 
>> This lead to the below mixing of libstdc++.so.6 and libc++/libcxxrt . . .
> 
> Yeah.  This is probably my fault.
> 
> We've baked the assumption into ports that "powerpc64 implies gcc in base".
> You're the first person to color outside the lines I think :-)
> 
> I'm going to start an internal discussion about what the "real" fix is.
> I consider what we've done in some places to not be the "real" fix because
> they assume _either_ llvm _or_ gcc in base.  This would fix your specific
> problem but not the general problem of someone installing both and then
> switching back and forth for testing.

Plus qt5 is outside the range of gcc 4.2.1 to cover, so for it
a usable "gcc in base" would mean base/gcc or some such substitution.
But base/gcc does not imply any version of libstdc++ is in use either:
same problem as system-clang-8-based if something like lang/gcc8 is
used for qt5.

Even if libstdc++ was (hypothetically) used, the vintage from
base/gcc or devel/*-gcc sorts of materials would not generally
match lang/gcc8 or whatever compiler:c++11-lib and the like
might default to.

For the likes of qt5, care must be taken that, for example,
devel/icu and its:

/usr/local/lib/libicui18n.so.64
/usr/local/lib/libicuuc.so.64

vs. qt5: they must use the same c++ library and vintage.

Then there are things that really could use gcc 4.2.1 from
base: mixed libstdc++ vintages could result, even if some
port lang/gcc* toolchain is used.

Definitely a messy context.

The failing behavior (program crash very early when starting)
was not obviously tied to c++ library mixes being involved. It
would be handy if some stage of building/installing/running
caught the presence of such a bad combination and was explicit
about it.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)